i asked mercedes themselves via email and this is the reply i got
Dear Sir
Thank you for contacting Mercedes-Benz Customer Service.
With reference to your email we received in our office on 22nd October 2014. Thank you for your enquiry regarding the paintwork of our vehicles. I have contacted our Technical Department and they have responded with the following answers to your questions:
The U on your paint code is an internal code and is not relevant in regards to the colour shade. The ceramic paint on Mercedes-Benz vehicles was introduced in 2003. Mercedes-Benz does offer solid black and white paints but this depends on the model of the vehicle whether or not this is available. Finally we may have offered two pack paints in the past but in recent times we have only used water based paints.
I hope that this answer is satisfactory for you and should you have any further requirements, please do not hesitate to contact us.
In our efforts to continuously improve our service to customers we would greatly appreciate your feedback, by way of a survey, to gauge your satisfaction with our brand. Please visit: www.dccac.net/qm/ukencsw and enter this case registration number: 1-4482666622. Thank you for your time.
Yours sincerely
David Sinclair
Customer Service UK
Phone No:
00800 9 777 7777 or 0207 660 9993
Mercedes-Benz Customer Assistance Center Maastricht N.V. Gelissendomein 5, 6229 GK Maastricht , Netherlands. Register No.: K.v.K. Limburg 33014909
by the way despite anything else i feel happy that as a owner of Mercedes-Benz even a 12 year old one i am able to contact the company and enquire about stuff and they will answer even technical things.
this method communication enhances the ownership experience, its good to be a part of a marque such as Benz
meanwhile the folks at Daimler AG i also emailed still sleeping:P